Remove mention/use of Python 2 from discussion about types.

Author: Paul Smith

ch00python/023types.ipynb

@@ -66,7 +66,7 @@
     "collapsed": true
    },
    "source": [
-    "Zero after a point is optional. But the **Dot** makes it a float."
+    "The zero after a decimal point is optional - it is the **Dot** makes it a float. However, it is better to always include the zero to improve readability."
    ]
   },
   {
@@ -142,109 +142,68 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The meaning of an operator varies depending on the type it is applied to! (And on the python version.)"
+    "The meaning of an operator varies depending on the type it is applied to!"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 1,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "0\n"
+      "3\n"
      ]
     }
    ],
    "source": [
-    "print(one // ten)"
+    "print(1 + 2)  # returns an integer"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "0.1"
-      ]
-     },
-     "execution_count": 8,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "one_float / ten_float"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "<class 'float'>\n"
+      "3.0\n"
      ]
     }
    ],
    "source": [
-    "print(type(one / ten))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 10,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "float"
-      ]
-     },
-     "execution_count": 10,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "type(tenth)"
+    "print(1.0 + 2.0)  # returns a float"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The divided by operator when applied to floats, means divide by for real numbers. But when applied to integers, it means\n",
-    "divide then round down:"
+    "The division by operator always returns a `float`, whether it's applied to `float`s or `int`s."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "3"
+       "3.3333333333333335"
       ]
      },
-     "execution_count": 11,
+     "execution_count": 4,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "10 // 3"
+    "10 / 3"
    ]
   },
   {
@@ -291,14 +250,32 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "So if I have two integer variables, and I want the `float` division, I need to change the type first."
+    "To perform integer division we need to use the `divmod` function, which returns the quotiant and remainder of the division."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "quotiant=3, remainder=1\n"
+     ]
+    }
+   ],
+   "source": [
+    "quotiant, remainder = divmod(10, 3)\n",
+    "print(f\"{quotiant=}, {remainder=}\")"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "There is a function for every type name, which is used to convert the input to an output of the desired type."
+    "Note that if either of the input type are `float`, the returned values will also be `float`s."
    ]
   },
   {
@@ -309,37 +286,64 @@
     {
      "data": {
       "text/plain": [
-       "float"
+       "(3.0, 1.0)"
       ]
      },
      "execution_count": 14,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
+   "source": [
+    "divmod(10, 3.0)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "There is a function for every built-in type, which is used to convert the input to an output of the desired type."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "float"
+      ]
+     },
+     "execution_count": 16,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "x = float(5)\n",
     "type(x)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 18,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "3.3333333333333335"
+       "(3.0, 1.0)"
       ]
      },
-     "execution_count": 15,
+     "execution_count": 18,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "10 / float(3)"
+    "divmod(10, float(3))"
    ]
   },
   {
@@ -1341,7 +1345,7 @@
    "display_name": "Types"
   },
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "Python 3.9.13 ('rsd-course')",
    "language": "python",
    "name": "python3"
   },
@@ -1355,7 +1359,12 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.7.3"
+   "version": "3.9.13"
+  },
+  "vscode": {
+   "interpreter": {
+    "hash": "56f3b33ce8ef81dba99c545090023eafaf7aedb33c344d352a9ab6fb4e2c3676"
+   }
   }
  },
  "nbformat": 4,